A high power wrenching tool, such as is described in U.S. Pat. No. 3,706,244 ("the 244 patent"), is now widely used on flanged connections. The 244 patent is assigned to the same assignee. Each full rotation of the wrench is usually limited to an angular excursion ranging between 30.degree. and 70.degree.. A drawback of such power wrenches is that, after each full rotation, the wrench must be lifted from the threaded connector on the flanged connection and repositioned for the next cycle of rotation.
A high-torque ratchet wrench for loosening or tightening nuts and bolts, which lends itself for applications such as are described in the 244 patent, but which overcomes the above mentioned drawback is described in U.S. Pat. No. 4,091,890 ("the 890 patent"), assigned to the same assignee.
The present invention is a power wrenching tool which utilizes the high-torque wrench described in the 890 patent. The wrench itself comprises two parallel side plates. Each plate has at one end thereof a bore. A ratchet wheel and a cooperating drive pawl are operatively mounted between the plates. The ratchet wheel defines at its center a socket and carries a plurality of angularly-spaced teeth on its circumferential periphery. A cylindrical boss outwardly extends from each side of the wheel. The bosses are rotatably mounted in the bores of the plates. The pawl has a base which is pivotable on or about a pivot which transversely extends between the plates. A pawl foot extends laterally and downwardly of the pivot. The pawl foot has teeth adapted to mesh with the ratchet wheel teeth. A pawl arm extends upwardly of the pivot. The pawl foot is adapted to receive from the pawl arm a radial force which urges the pawl foot teeth to engage with the ratchet wheel teeth, and a tangential force which rotates the ratchet wheel.